Gas scrubber



May 14, 1929. G, FAST 1,713,175

GAS sc RUBBER Filed May 28, 1925 e sheets-sheet 1 gwuamtoz May 14, 1929*. y G, FAST f I 1,713,175

GAS SCRU-BBER Filed May 28, 1925 6 Sheets-Sheet 2 l .f'ylff May 14, 1929. G, FAST 1,713,175

GAS SCRUBBER 4 Filed May 28, 1925 6 Sheets-Sheet 5 muto@ fm. www

May 14, 1929. Q FAST v 1,713,175

GAS SCRUBBER Filed My 28, 1925 e sheets-sheet 4 rlIlIIlllllllllIl/ May 14, 1929.

G. FAST GAS SCRUBBER Filed May 28,' 1925 6 Sheets--SheekI 5 I in place. f

of thae apparatus.

Patented 14,1929. i

UNITED -s'rzrrlas" i GUsTAvE FAST, or ANNAPoLIs, antan-.M111

Gas Schumann.

' Application 1edlfay 28,

The invention concerns an apparatus for scrubbing gas and removing dust jandrecovering the valuable by-products and it consists in the features and combination and arrangement of parts hereinafter described; and particularly pointed out'in the claims.

In the .accompanying drawings Figure l is a side elevation of one form Fig. 2 is a transverse section substantially online 2-2 of Fig.` 1.

` Fig. 3 is a plan view.

Fig. 4 is a longitudinal section substantially on line 4 4 of Fig.. 2 through one of the units of the casing withthe spray nozzleA Fig. 5 is a longitudinalvertical section through one form of nozzle. n

Fig. 6 is. a transverse section ofFig. 5 through the volute on the line 6 6.

Fig. 7 is a modification of theapparatus arranged vertically instead of horizontally.

The apparatus is composed of units each havingy itsown spray device and itspowerl plant for forcing the washing liquid through the spray device and these units may ybe assembled in any desired number for making the apparatus of greater oi' lesser extent as may vlbe desired, and in adding or subtracting units'thepower plants of the other units are not altered and each is capable of adjustment to secure a greater velocityof its spray, as Well as changes inl the temperature of its spray independent of the other units. i

The apparatus may be arranged hor1zontally or vertically, and in either case units may be addedor taken away andthe independence of the other units as to their individual operation and modification of said operation and effects will not be interfered with.

In the apparatus asJ embodied in horizontal 'form a plurality of casing or units 1 are arranged side by side and connected by their flanges 2. Each unit has a casing of general form as shown in Fig. 4, which represents a longitudinal section of the casing unit.

Each unit may have a removable top plate 3 and held to the main body by flanges screwed or bolted thereto.

Each unit has a skirt portion/f which is flanged for attachment to suitable supporting channel beams 5 extending lengthwise of the apparatus and resting upon 'the walls 1925. seriarNo. 33,428.

6 of tanks 7a which preferably are arranged below the vsurface 'of the ground. There is one of these tanks for' each unitand the division walls betweenthe tanks 'are indicated at 8. Eachunit has a spray device therein shown generally at 9, each of which produces two annular sprays of liquid indicated at 0;, b, which extend transversely across the unit at points 'between the inlet o and the outlet dfor the gas to .and from- 'said unit.

Each unit also has a centrifugal pump l10 which is driven by its own motor shown generally at `11 by which each pump may be driven independently of. the `other pumps. The pump gets part -of its supply from the tank to which it belongs through an inlet pipe 12, and forces the liquid to and' through the spray device by way of the pipe 13. This pipe has branches 13, 13b leading respectively'to the two sections of the spray'device 9 toproduce the two sprays a, b, as will be described later. l v

The pump also gets what fresh cool liquid may be neededthrough a supply pipe-23 connected with any suitable ysource which' has branches 24leading to the pumps with lvalves 25 for regulating this supply. Other valves 26 regulate the amount of liqui to be drawn from the tank, and" byy means of these valves thel proportion of fresh cool liquid drawn through the pipe23 and 24 can b'e regulated in respect to -that drawn from the tank, which owing to recirculation through the unit may be more or less'heated,l

and thus at each unit the character of the spray liquid may be regulated to suit the lrequireme ts. at that point. The volume of liquid deli ered to the spray device may be regulated by the valve 27 according to "requi'rement's.

The dischargefrom through a pipe 14 Which has an upwardly turned lower. end 15 which directs-the dis'- charge upwardly towards the lgate 16 for the overflow of liquid from the tank to a each unittakes place i structure.

through the units l and discharges through the moisture eliminator indicated generally at A which receives the gas from the left hand unit through the pipel21 and {ina-l discharge of clean, dry gas takesplace from the apparatus up through the discharge pipe 22.

The spray devices are designed to produce fine sprays of liquid projected from the center of the units transversely thereof, said sprays having a motion in a direction around the axis of the unit. In producing the spray I employ a member or members having a channel 9 c of volute form and of diminishing cross sectional area from inlet to outlet. In the form shown generally at 9, A9a there are two of these volute o r spiral channels in the same organization, these being reversed in respect to'each other. The oriiice 9b of oneof thesekspiral nozzles is directed towards the right Aand the oriiice 9c of the other nozzlev or volute channel is directed towards the left.

The liquid passing through these volute tapering nozzles attains high velocity and issues from the annular orifice under high centrifugal force which 'causes it to pass along the Haring wall 91 and the Haring screen 9e, and through the perfor-ations kin the latter and thence transversely of the space 27 between `the nozzle or spray member and theopposite wall of the casing of the unit, where it is broken into a fine mist or fog, it being understood as illustrated that the axis of the spray device coincides approximately with the axis of the units.

The motion of the liquid derived from its passage through the volute channel is rotative in respect to the axis of the unit and the gas stream of course has a general direction horizontally along the units, so that the direction of the gas stream brings it into intimate contact with the spray, and as a result the direction of the gas stream in passing through the spray is changed to accord therewith and owing to the fact as above stated that the nozzle sections 9, 9DL are reversed, in respect to each other and their directions of rotative action' are4 relatively reversed, the gas stream is subjected to change of direction on striking each of the spraysv and its intimate contact therewith is enhanced. The screen member breaks up the water into a state of tine sub-division in which condition it extends across the path of the gas. Thescreen may be stationary or it may be mounted so as to rotate about the axis of the unit. 'In Fig. 5 lthe screen is shown as carried by a hollow shaft or sleeve 28 turnable on bearings 29, on the journals 30'forming extensions of the nozzle or volute The edge 3l of the screen engages a channel. 32 in the housing. The screen material is held by rings 33, 34 and tie rods 35 connect thering 33 with the hol'- low shaft. The ring 34 is carried by the spider 36 which forms a support for the end of the screen. The screen member may be caused to rotate by the swirling action of the liquid thereagainst or I may provide a ring of turbine blades 37 against which the water strikes after issuing from the orilic'e 9b or'9c of the volute nozzle structure for "thus rotating the screen and thereby acchannels are provided at 39, 40 through which a portion of the water is taken from the volute channel and is directed to said bearings.

One of the volute structures receives its supply of water through the branch pipe 13a and the other throughthe branch pipe 131 previously mentioned.

The openings of the screen as shown in `VFig. 5 maybe other than circular. in order to effect the breaking up of the Water and these openings may be arranged in a spiral line to accord with the spiral course of the water as it flows along and around the screen. f

By my invent-ion I remove undesirable minute particles of solids and vapors from a gas such as for instance blast furnace or producer gas by means of wet scrubbing and condensation, and recover the valuable products such as tar, ammonia, etc., from coal gas or gasoline from natural gas by means of condensation and concentration.

The apparatus will effect a complete penetration of the gas by the liquid resulting in a complete emulsifying of the solid particles and a high rate of thermal exchange be! tween the gas and liquid and therefore rapid cooling with-'corresponding condensation of vapors.

The spray is distributed in a yiinely subdivided state uniformly over the entire cross sectional area of the gas stream in order to avoid gas channelling through portion of the liquid spray of less density should the` spray lack the uniformity just mentioned.

Change in the direction of the gas stream is conducive to theV separationtherefrom of the dust or solid particles.

This is secured in myapparatus by the 'rotative sprays which in succession 'alternate in direction of their rotative movement. j

It is also secured by the general sinuous path followed by the gas due tothe shape of the casings of the units which las shown in Fig. 4 'have comparatively contracted enitrance and exit openings, and centrally disposed nozzles or -spray devices past which the gas passes and is deflected from its straightcourse. Contributing to this also is theshape of'thespray devices with their Haring screens.

On striking a spray the gas tends to follow the rotative direction thereof and on leaving this sprayit will be subjectedto eddyy currents induced by the shape of the spray device or rather its conical screens, and this is a factor which accentuates the intimate contact of the gas and liquid.

If contrary to the above all the sprayshad rotative movement in one direction the gas would attain a spin or rotative action al- -ways in the same direction and the same degree of intimate contact will not be attained.

Contributing als@A to the separating action is the changes at different points of its course of the velocity of the gas stream. This is due to the variations in the cross sectional area of the path of the gas stream at different points, as evidenced by the differ-- ence in area between the inlet or the outlet of a unit and the central part of the unit Where the. gas stream assumes an annular form in passing by the spray devlce, and also contributing to this action is"'the difference in diameter at therrims of the conical Screens.

The first spray i. e. the 'one at the right of the apparatusis sensibly Warm, say- 150 l1".

due to its recirculation in contact With the hot dirty gas andpon meeting this warm spray first the solid particles will emulsify to a degree that would not be accomplishedif thisspray were cold. .Each succeeding spray is ,cpoler than the preceding one, thus condensing more of the vapors, the amount condensed lcorresponding to the dew point as controlled by the temperature and' pressure in the spray chamber.

The last spray i.,e. that at the left of the apparatus should be only a few degrees below the temperature of the cleaned gas.

The temperature of each spray, unit can be altered individually and independentlyY At the last Aunit nearly alll the scrubbingl liquid used is taken from the outside source, that is to say it is as clear and as cool as possible, and very little, if any, li uid vis reeirculated from the storage tank elonging to this unit. At the other units very little, if any, scrubbing fluid is added.

i The' overflow from the tanks through the outlets 16 goes to settling vats or thickeners for the recovery of the dust or it may go to waste.

The overflow gates from the tanks are controlled by V shaped adjustable plates 16a. By adjusting these gates in conjunction with the control of the fresh water'supply, the temperature' .of the liquid spray at each unit can -be regulated.

At the discharge end of the apparatusa moisture entrainment eliminator? A is employed as before mentioned.

This istused to remove any of the scrubbing liquid which still may be entrained as moisture in the gas after the dust has been removed, and the gas cooled to a point where most of the vapors have been condensed.

By passing the gas through the tortuous passages in the scrubbing chambers as well as the entrainment eliminator a considerable portion of the original gas pressure head is lost and in the event that the gas has to be sent some distance to its ultimate destination it is sometimes required to boost the pressure of the gas. l As generally very large quantities of gas cis being handled any boosting device handling the entire quantity becomes very large, unwieldy and ineili'cient. i

ftherefore use only a small portion of the total gas for boosting purposes circulating same, from chamber 4.6 through supply connections 50, through a fan or blower of theI closed type as shown at 49.

By increasing the pressure of this small portion of the gas through the Y'blower and allowing it to escape through a properly shaped nozzle 51 at high velocity the pressure of the gas jet is so reduced as to form au partial vacuum at the smallest part of the dischargeA pipe, thus augmenting the flow of the entire gas stream. The divergent discharge pipe will convert the velocity head of the gas stream into pressure head as the velocity decreases.

As previousl explained, the motive power or energy of t e sprays is produced/by the centrifugal pumps and no other power of any kind is supplied to the scrubber proper.

The liquid entering under a considerable pressure head deriveskinetic energy through increased velocity in passing through the yspiaally shaped volute ofconstantly chang-l ing area and radius thus attaining a considcrable centrifugal head.

When allowed to escape through the annular orice or vortex 9"-, 9b, it will rapidly ascend the sides of the vortex chamber 9d with a'high rotational velocity The liquid then runs onto the screen, s reader or diffuser which breaks the liqui up into a fine spray ory mist.

. This diffuser may be either stationary or revolving.

makes it easier to balance.

The diffuser may be driven eitherby friction from the rotating spray or through a small turbine element which will utilize part of the liquid velocity for driving the diffuser.. 'i

The entire body of the liquid may .bei

thrown against the perforated diffuser or it 'may be distributedevenly over the perfo-` rated diffuser by means of plate cones 9*- as shown terminatingat different points of the' di'uvser.

The inlet piperto the .volute may beprovided with a twisted .vane or vanes giving the liquid a rotational spin about an axis. parallel to the direction of flow.

This will produce considerable eddy currents in the vortex or annular orificel which Aassist in breaking up of the liquid as it strikesA the diffuser thus producing a finer spray.v ,A

Instead of-arranging the apparatus horiL zontally it may, as shown in Fig. 7,' be ar-. ranged vertically.

The same spray' nozzles as above described may be used in this form of the apparatus and the apparatus may be composed rof separable units, each of which has its own circulating system. r r

In this form each unit will have partitions or annular plates 52 for delivering the spray water to the pans or troughs 53 having an outlet twhich is connected with the tank belonging to that unit. The gas enters at 55 and passes up in the circuitous path indicated by the arrows through the sprays to the .upper outlet and it is subjected to the actions above described lin connection with the first form, and the individual character of the units may be varied as in the-form rst described.

The casings of the units in which the Yspray nozzles are located may -be of a variety of forms. These units may be of cylindrical 'form with partitions betweenthem having openings in line with the axis of the cylindrical forms for the passage of the gas, i Y and the gas in passing through the units and f past the spray nozzle willassume va course in which the` direction of movement will be constantly changing, and further, lthe velocity of the gas willl be constantly changing owing to the variation in cross-sectional .area of the gas path at different points along the same. i

While I have describeddiii'users having rotary parts, I do not limit myself in this respect. l

I clainr: A

l. A as scrubber comprising a casing adapted Ior the passage of gas therethrough, a plurality of nozzles for directing rotative sprays of liquid transverselyv of and at all points around said casingand through which sprays the gas passes, one of said sprays rotating. in the opposite direction from an-I other of said sprays to change the direction of movement of the gas in its passage through the casing, each of said Ispraysbeing regulatable as to temperature and velocity independently of the other spray substantially as described.- v

2. In combination in a gas scrubber, a casing adapted for the passageof gas therethrough, a' plurality of spray producing means disposed at separated points along said casing, veachxspray means having its own circulating system for the spray liquid, each circulating system having its own tank vwhereby the spra'yliquid of each system is kept substantially separate from the spray liquid of each other system, and means forsupplying cooll water to each system for independent regulation of the temperature ofeach spray substantially as described.

3. In combination in a gas scrubber, a casing adapted for the passage ofl gas therethrough, a plurality of spray producing means disposed at separated points along said casing,l each spray means having its own circulating system for the spray liquid, .each circulating /system having its own tank whereby vthe spray liquid of each system 'is kept substantially separate from the spray liquid ofeach other system, means for supplying codl water to each system for independent regulation of the temperature.. of eachJ spray, and an overflow connection from tank to tank, substantially as de scribed.

In testimony whereof I afiix my signature.

GUsTAvE FAST. 

